AP Macroeconomics Quiz: Price Indices And Inflation

What this quiz covers

This quiz focuses on Price Indices And Inflation, giving you a quick way to practice the rules, question types, and explanations that matter most for AP Macroeconomics.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. From 2022 to 2023, because the CPI rises from 100 to 104.
2. From 2023 to 2024, because the CPI rises from 104 to 112. (correct answer)
3. From 2022 to 2024, because the CPI is highest in 2024.
4. From 2022 to 2023, because 2022 is the base year and prices are normal then.
5. From 2023 to 2024, because the CPI is above 100 so inflation must be negative.

Explanation: Inflation is the rate of change in the price level, measured as the percentage change in a price index like the CPI. In this problem, we need to calculate inflation rates for each period: from 2022 to 2023, the CPI rises from 100 to 104, giving an inflation rate of (104-100)/100 = 4%. From 2023 to 2024, the CPI rises from 104 to 112, giving an inflation rate of (112-104)/104 ≈ 7.7%. The highest inflation rate occurs from 2023 to 2024, making answer B correct. A common misconception is confusing the price level (the CPI value) with the inflation rate (the percentage change in CPI). Remember: inflation equals the rate of change of the index, not the index level itself.

Question 2

1. From 2021 to 2022, because the CPI rises from 100 to 106.
2. From 2022 to 2023, because the CPI rises from 106 to 107.
3. From 2023 to 2024, because the CPI falls from 107 to 105. (correct answer)
4. From 2021 to 2024, because the CPI is highest in 2023.
5. From 2022 to 2023, because the CPI is above 100 in both years.

Explanation: Inflation is the percentage change in the price level between periods, and deflation occurs when this change is negative. Calculating each period: from 2021 to 2022, (106-100)/100 = 6% inflation; from 2022 to 2023, (107-106)/106 ≈ 0.9% inflation; from 2023 to 2024, (105-107)/107 ≈ -1.9% deflation. The period from 2023 to 2024 has the lowest inflation rate (actually negative, indicating deflation), making answer C correct. The key insight is that when the CPI falls, we have deflation—a negative inflation rate that is lower than any positive rate. Remember: inflation equals the rate of change of the index, and this rate can be negative when the index decreases.

Question 3

1. The price level in 2021 is 10% higher than in 2019. (correct answer)
2. The inflation rate in 2021 is 10% because the deflator equals 110.
3. The price level in 2021 is 10% lower than in 2019.
4. The inflation rate in 2021 is zero because 2019 is the base year.
5. The price level in 2021 is normal because the base year sets normal prices.

Explanation: Inflation measures the rate of change in prices, while the price level compares prices at different points in time. With a base year of 2019 (deflator = 100), a deflator of 110 in 2021 means the overall price level in 2021 is 110% of the 2019 level, or 10% higher than in 2019. This is a statement about relative price levels, not about the inflation rate in any particular year. Answer A correctly interprets this relationship. A common error is confusing the deflator value with the inflation rate—a deflator of 110 doesn't mean 10% inflation in that year, but rather prices 10% higher than the base year. Remember: inflation equals the rate of change of the index between consecutive periods, while the index level shows cumulative price changes from the base year.

Question 4

1. From 2020 to 2021, because the CPI rises from 100 to 103.
2. From 2021 to 2022, because the CPI falls from 103 to 99. (correct answer)
3. From 2022 to 2023, because the CPI rises from 99 to 102.
4. From 2020 to 2023, because the CPI is above 100 in 2023.
5. From 2021 to 2022, because the CPI is near 100 so prices are normal.

Explanation: Inflation is the percentage change in the price level, while deflation occurs when this change is negative. Looking at the CPI movements: from 2020 to 2021, CPI rises from 100 to 103 (positive inflation of 3%). From 2021 to 2022, CPI falls from 103 to 99, giving a change of (99-103)/103 ≈ -3.9%, which is deflation. From 2022 to 2023, CPI rises from 99 to 102 (positive inflation again). Only the period from 2021 to 2022 shows deflation, making answer B correct. A common error is thinking deflation occurs whenever the CPI is below some threshold like 100—deflation only occurs when the CPI decreases. Remember: inflation equals the rate of change of the index; deflation means a negative rate of change.

Question 5

1. Yes; a higher CPI level always means a higher inflation rate.
2. Yes; because the CPI is above 100 in both 2023 and 2024.
3. No; inflation depends on the percent change in the CPI, not the CPI level. (correct answer)
4. No; inflation must be negative whenever the CPI is above 100.
5. No; the base year indicates the only year with zero inflation.

Explanation: Inflation is defined as the percentage change in a price index, not the level of the index itself. The student's claim confuses these two concepts—a higher CPI level in 2024 doesn't automatically mean higher inflation that year. Inflation in any year depends on how much the CPI changed from the previous year, calculated as (CPInew - CPIold)/CPIold × 100%. For instance, if CPI goes 100→110→115, inflation is 10% then 4.5%, showing that inflation decreased even though the CPI level increased. Answer C correctly identifies this distinction. The fundamental misconception is equating price level with inflation rate. Remember: inflation equals the rate of change of the index, not the index value itself.

Question 6

1. From 2022 to 2023, because the deflator rises from 100 to 102.
2. From 2023 to 2024, because the deflator rises from 102 to 108. (correct answer)
3. From 2022 to 2024, because the deflator is highest in 2024.
4. From 2022 to 2023, because the base year implies the largest change.
5. From 2023 to 2024, because a higher deflator means lower inflation.

Explanation: Inflation is calculated as the percentage change in a price index between periods. From the given data: from 2022 to 2023, the deflator rises from 100 to 102, giving inflation of (102-100)/100 = 2%. From 2023 to 2024, the deflator rises from 102 to 108, giving inflation of (108-102)/102 ≈ 5.9%. The higher inflation rate occurs from 2023 to 2024, making answer B correct. The error in thinking the base year matters for inflation calculations stems from confusing absolute changes with percentage changes—what matters is the proportional change, not where we start. Remember: inflation equals the rate of change of the index, calculated as percentage change regardless of the base year.

Question 7

1. From 2020 to 2021 because the GDP deflator rises by 2 points.
2. From 2021 to 2022 because the GDP deflator is higher in 2022 than in 2021.
3. From 2022 to 2023 because the GDP deflator is highest in 2023.
4. From 2021 to 2022 because a 4-point rise is a smaller percent change than a 2-point rise from 100. (correct answer)
5. From 2020 to 2023 because the GDP deflator stays above 100 throughout.

Explanation: Inflation is the percentage increase in the price level, with lower positive rates indicating slower but still positive price growth, tracked by indices like the GDP deflator. The table, base year 2020 = 100, presents deflator values rising across periods, with varying point increases. The period from 2021 to 2022 had the lowest positive inflation because its 4-point rise, from a higher base, results in a smaller percentage than a 2-point rise from 100 would. This follows as larger point changes from elevated bases can yield lower rates, depending on the data. A misconception is assuming smaller point changes always mean lower inflation, but it's the percentage relative to the base that counts, distinguishing level from rate. Here, the comparison illustrates how base effects influence rates. The transferable rule is that inflation is the rate of change of the index, crucial for identifying comparative rates.

Question 8

1. Inflation was higher in 2023–2024 because the CPI is higher in 2024 than in 2023.
2. Inflation was the same in both periods because the CPI increased by 4 index points each year.
3. Inflation was lower in 2023–2024 because the CPI increased by a smaller percent in that period. (correct answer)
4. Inflation was lower in 2022–2023 because the CPI remained above 100 in both years.
5. Inflation was zero in 2023–2024 because the base year is normalized to 100.

Explanation: Inflation measures the percentage increase in the overall price level from one period to another, using tools like the CPI to track these changes. Based on the table with base year 2021 = 100, the CPI increases by 4 index points each year, but the percentage change is smaller in 2023–2024 due to the higher starting value. Thus, inflation was lower in 2023–2024 because the same point increase represents a smaller relative rise compared to 2022–2023. This follows from calculating the rates: 4 points from a lower base yields a higher percentage than from a higher base. A common misconception is assuming equal point changes mean equal inflation, but the rate accounts for the base level, distinguishing level from rate. For example, inflation slows as the index grows if point changes remain constant. The transferable rule is that inflation is the rate of change of the index, specifically the percentage shift, not the raw point difference.

Question 9

1. The price level increased by about 5% because the GDP deflator rose from 105 to 110. (correct answer)
2. The price level decreased by about 5% because the GDP deflator rose from 105 to 110.
3. The price level increased by 10% because the GDP deflator in 2024 is 110.
4. The price level did not change because the GDP deflator stayed above 100.
5. The price level returned to normal because the base year equals 100.

Explanation: Inflation describes the rate of increase in the average prices of goods and services, expressed as the percentage change in an index like the GDP deflator. The table indicates the GDP deflator rises from 105 in 2023 to 110 in 2024, with base year 2022 = 100. The price level increased by about 5% because the calculation ((110 - 105)/105) × 100 approximates 4.76%, close to 5%. This accurate description stems from focusing on the percentage change between the two years, not the absolute values or base year comparisons. One misconception is viewing the rise to 110 as a 10% increase from the base, but that's cumulative, not the annual rate. Instead, the change is relative to the prior year's level. The transferable rule is that inflation equals the rate of change of the index over the period, providing a measure of current price dynamics.

Question 10

1. From 2022 to 2023 because the CPI level is higher in 2023 than in 2022.
2. From 2023 to 2024 because the CPI increases by a larger amount than in the prior year.
3. From 2024 to 2025 because the CPI is highest in 2025.
4. From 2022 to 2023 because the CPI rises by 6 points, which is a larger percent increase than later. (correct answer)
5. From 2024 to 2025 because the CPI remains above 100, indicating faster inflation.

Explanation: Inflation is defined as the sustained increase in the general price level of goods and services in an economy over a period of time, measured by the percentage change in a price index like the Consumer Price Index (CPI). In the table, the CPI begins at 100 in the base year 2022 and rises in subsequent years, allowing us to calculate year-over-year changes. The highest inflation rate is determined by the largest percentage increase, which occurs from 2022 to 2023 where a 6-point rise from 100 represents a 6% change, larger than the percentage changes in later periods due to the increasing base. This follows because inflation focuses on the relative change, not absolute points or the final index value. A common misconception is equating a higher CPI level with a higher inflation rate, but the level reflects cumulative price changes, while the rate is the annual percentage shift. For instance, later periods might show smaller percentage increases even if point changes are similar, as the denominator grows. The transferable rule is that inflation equals the rate of change of the index, calculated as ((new index - old index) / old index) × 100.